1. Field of the Invention
The present invention relates to a development apparatus that uses developer to develop an electrostatic latent image formed on an electrostatic latent image carrier and an image forming apparatus containing the development apparatus.
2. Description of Related Art
Conventionally, an image forming apparatus using an electrophotographic recording method is known to form an image by heat fusing a developer image onto a prescribed recording medium. This type of image forming apparatus, as shown, for example, in Japanese Patent Application Publication No. 10-39628, forms an image through a series of processes, which are a charging process that charges a photosensitive insular layer forming a photosensitive body with a uniform voltage, an exposure process that forms the electrostatic latent image on the photosensitive body by eliminating charge on a portion that was exposed by irradiating the photosensitive insular layer with modulated light based on image data, a development process that visualizes the electrostatic latent image by affixing developer (hereinafter referred to as toner) that includes at least coloring to the formed electrostatic latent image, a transfer process that transfers the visible image to a transfer material such as transfer paper (printing medium), and a fusion process that fuses the visible image on the transfer material using heat and pressure, or any other suitable fusion method.
However, in the conventional image forming apparatus described in the aforementioned patent document, toner that is charged and thinned to a uniform thickness cannot be steadily supplied because of the deterioration of a development roller, toner supply roller, and toner caused by friction between the toner supply roller that supplies toner to the development roller and the development roller that affixes toner to the photosensitive body by rotating and contacting the photosensitive body. This inability to steadily supply toner results in a decrease in quality of the printing material. In addition, in the conventional image forming apparatus, because the a large amount of torque is necessary to drive the rotation of the development roller and the toner supply roller, irregularities arise in the rotation in a case where an operation is performed quickly, causing a decrease in the quality of the printing material.